1. Field of the Invention
This invention relates to a honeycomb structure comprising a paper or structural sheet of aramid materials impregnated by a solid matrix resin wherein the honeycomb exhibits a light weight, a high shear strength/modulus, an excellent stability to moisture and high temperature, and excellent corrosion resistance, toughness, and fatigue performance.
2. Description of the Prior Art
U.S. Pat. No. 4,710,432 issued Dec. 1, 1987 on the application of Nishimura et al., discloses preparation of a polyester paper comprising drawn and flattened polyester fibers. The paper is used to make honeycomb. Honeycomb made from paper comprising fibers of poly(m-phenylene isophthalamide) is mentioned as being in the prior art.
Japanese Kokai Publication 60-36152, published Feb. 25, 1985 on the application of Yamamoto et al., discloses a two-component, nonwoven, aramid paper for use in the manufacture of honeycomb. One of the paper components is a drawn fiber and the other is a non-drawn fiber. There are no binder fibers in the construction.
Japanese Kokai Publication 62-223398, published Oct. 1, 1987 on the application of Nishimura et al., discloses a two-component, nonwoven, paper wherein one of the components is a strong fiber which can be aramid, and the other component is a polyester fiber of low orientation. The paper can be used for honeycomb.
U.S. Pat. No. 4,729,921, issued Mar. 8, 1988 on the application of Tokarsky, discloses preparation of aramid papers using aramid floc, aramid fibrids, and, optionally, aramid pulp. The papers are said to be useful for laminating printed circuit boards.